How do we know that grace does not run in the bloodline?

The idea that grace does not run in the bloodline is drawn from John 1:13, which states that being born again is 'not of blood.' This means that spiritual life and the new birth are not transmitted through family lineage but are sovereignly bestowed by God. Josiah, a righteous king, had ungodly sons who did not follow his ways, demonstrating that each individual must experience God's grace personally. Salvation is an individual matter, reliant solely on God's grace rather than familial ties.